At present, a general temperature control scheme for an electronic apparatus, especially for a computer, is shown in FIG. 1. As shown, a super input/output (I/O) interface reads a CPU temperature, compares it with a temperature control parameter stored in a Basic Input Output System (BIOS), and then output a corresponding duty cycle as a control parameter to a CPU fan and a system fan for controlling them to operate at corresponding rotational speeds.
In controlling respective fans according to prior art, a linear temperature control scheme is adopted, as shown in FIG. 2. In this case, the CPU temperature is shown as a difference from an overheating protection temperature, Tdts, and thus is typically negative. When the CPU temperature is lower than a certain temperature, the CPU fan and the system fan are set to operate at a minimum rotational speed. When the CPU temperature is higher than a certain temperature, the CPU fan and the system fan are set to operate at full rate or a predetermined rate. And when the CPU temperature lies between a lowest temperature and a highest temperature, the rotational speeds of the CPU fan and the system fan are set to increase/decrease linearly at a predetermined slope with the increase/decrease of the CPU temperature.
In implementation of the present invention, the inventors have discovered at least the following problems with the prior art. Due to the difference between a temperature required for heat dissipation test (e.g., a high temperature of 35 degrees) and a temperature required for noise test (e.g., a room temperature of 23 degrees), the high and low temperatures correspond to different temperature control profiles, respectively. Further, a housing in which the apparatus resides may have different volumes and layouts, which results in different heat dissipation efficiencies during air circling. However, the existing temperature control schemes are typically based on only one temperature control profile, and cannot satisfy requirements on both temperature control and noise in various temperature conditions due to incapability of monitoring the ambient temperature of the apparatus.